Many modern broadband wireless access systems (e.g., WiMAX) use space-time signal processing that exploits multiple antennas at the transmitting (TX) and receiving (RX) ends of the communication link. Future systems (e.g., WiMAX II) are expected to further improve performance by applying a number of advanced techniques like multi-user (MU) multiple-input/multiple-output (MIMO) transmission. There is a need for beamforming techniques that may be used in the downlink of a multi-user MIMO network.